Lighting fixture



NOV 9, 1965 E. M. cAFERRo ETAL 3,217,155

LIGHTING FIXTURE Filed May lO, 1963 4 Sheets-Sheet 1 ATTYs.

EDWARD N. Caf-Ans BYwm/AM 5. HERoAN LIGHTING FIXTURE 4 Sheets-Sheet 2 5. Y T OR M M mn R am mm. 6.6/ 0M Mm wu. ww

N0V 9, 1965 v E. M. cAFERRo ETAL med May 1o, 196s Nov. 9, 1965 F'iled May lO, 1965 E. M. CAFERRO ETAL LIGHTING FIXTURE 4 Sheets-Sheet 3 INVENTORQS EDWARD M. CAFERRo BY WILL/AM 5. HERDAN ATTYS.

NOV- 9, 1965 E. M. cAFERRo ETAL 3,217,155

LIGHTING FIXTURE Filed May lO, 1963 4 Sheets-Sheet 4 29 9 29 29 lso al MLLLLLLLM////////////////////ML INV TORS EDWARD M. AFERRo .WILLIAM 5. HERDAN ATTYs.

United States Patent O 3,217,155 LIGHTING FIXTURE Edward M. Caferro, Spokane, Wash., and William S. Herdan, Chatworth, Calif., assignors to Columbia Electric & IManufacturing Company, Spokane, Wash., a corporation of Washington Filed May 10, 1963, Ser. No. 279,459 7 Claims. (Cl. 240 9) This invention relates to a novel lighting fixture designed particularly for use in the ceilings of clean rooms, such as are used for biological experimentation and electronic component manufacturing.

Due to the increasing complexity and refinement of both biological and electronic research in recent years, there is an increasing necessity to provide work rooms which are extermely clean both as to surface and atmosphere. Various degrees of cleanliness are specified for specific applications. In ultimate circumstances the atmosphere itself must be completely free of all particles down to and including virus sizes.

Rooms such as this must naturally be lighted, since they will usually not include any windows. Lighting fixtures require maintenance, and the introduction of replacement lamps, which might be contaminated. It is therefore advisable that the lighting fixtures be isolated from the room interior so that they might be serviced without entering the room.

It is a first object of this invention to provide a novel lighting fixture which incorporates into the fixture a catwalk on which a person may walk in order to service or clean the fixture without entering the room being lighted thereby. The invention is 4concerned with removing the necessity of separate catwalks and accomplishes this by combining the catwalk and xture as a unit.

It is another object of this invention to provide such a lighting fixture which can be mounted entirely above a panelled false ceiling structure so that the lighting fixture is completely isolated from the room interior and never requires maintenance from below the ceiling surface.

Another object of this invention is to combine the lighting fixture and approach catwalks in such a manner that the catwalks improve the accessibility of the fixture components. More particularly, it is envisioned that the fixture reflectors will be mounted on the catwalks and will be movable therewith so that one need only to lift a catwalk for complete access to the fixture, lamps and panels.

These and further objects will be evident from a study of the following disclosure taken in conjunction with the accompanying drawings which illustrate a preferred form of the invention. It is to be emphasized that the specific structure of this form is exemplary and is not intended to restrict or confine the scope of the invention, which is set out in the claims that follow.

In the drawings:

FIGURE l is a fragmentary sectional View taken through a vertical transverse plane, showing the fixture as mounted in a ceiling installation, the raised positions of the catwalk being illustrated in dashed lines;

FIGURE 2 is a fragmentary sectional view taken along line 2 2 in FIGURE l showing the area where one longitudinally aligned fixture joins another;

FIGURE 3 is a top plan View of the mounted fixture taken along line 3 3 in FIGURE l;

FIGURE 4 is a view of the xture as seen in FIG- URE 3, taken along line 4 4 in FIGURE l;

FIGURE 5 is a schematic longitudinal view showing the installation of the fixtures in a room; and

3,217,155 Patented Nov. 9, 1965 ICC FIGURE 6 is a transverse view similar to FIGURE 5.

Referring now to the drawings and in particular to FIGURES 5 and 6, the present lighting fixture is designed particularly for clean rooms, wherein the room surfaces and the atmosphere in the room are free of dust and other particles down to a specified size. In such a room, all air is normally filtered and anything entering the room is washed. Entrance is gained through air locks. The rooms normally have an interior pressure greater than the exterior pressure about the rooms, so that no dust can filter into the room through cracks or small openings. In FIGURES 5 and 6 the room is shown with a true ceiling designated by the numeral 11 and a false ceiling comprising panel sections 29 located at a distance below the true ceiling 11 so that a man can comfortably walk in the area separating these two ceiling sections. The room has walls 30 and a fioor 31 so that the room interior is actually bounded by walls 30 or 31 and the ceiling panels 29. This is the area which shall be referred to herein as the interior of the clean room.

The present fixture is adapted to be mounted with all of the lamp components at an elevation above that of the panel sections 29. It is the primary purpose of this device to provide a fixture which is readily accessible within the area between the true ceiling 11 and the panel sections 29 which form the ceiling of the clean room.

With reference to FIGURES l and 2, which show the details of the fixture, the fixture basically comprises a combination catwalk and fluorescent lamp structure. The fixture is hung from the true ceiling 11 by a series of vertical tie rods 10 which are connected to the ceiling 11 by brackets 10a. At the lower end of each tie rod 10 is a channel hanger 12 mounted in a vertical position. Extending transversely between each pair of channel hangers 12 are transverse angles 14 mounted back-to-back in the manner shown by the sectional view of FIGURE 2. The angles 14 are secured to the channel hangers 12 by bolts 13a. The two angles 14 are secured to one another by bolts 13 located longitudinally across the length of the angles 14.

The channel hangers 12 also support longitudinal circuit and fixture wireways 16 which extend along the length of the fixtures directly below the angles 14 and at the side extremities thereof. The wireways 16 include an inner wall which is designated as 17 and which extends downwardly to provide lower supporting ledges 18 for the panel sections 29 and for light conductor panels 19 which might be fabricated of glass, plastic, or other suitable material. Extending transversely from the lower portions of the extensions 17 are transverse connectors 20, providing a rigid connection between adjacent light fixtures which are normally mounted in longitudinally arranged rows in the manner shown in FIGURE 6. Thus the rows of fixtures, although hung from tie rods 10, have both longitudinal and transverse members joining one another and abutting the walls 30 so that the entire assembly when completed is quite stable and rigid.

The structure of this fixture contemplates a continuous false ceiling including the panel sections 29, the light conductor panels 19 and possible perforated panels usable for air conditioning purposes. The entire structure of the lighting fixture is situated above this false ceiling structure.

The fixture itself includes transverse sections 2S which are fixed to the angles 14 and extend directly below these angles 14 as seen in FIGURE 2. The fixture sections include room for necessary ballast and the lamp sockets 26, as well as the wiring for the lamps. The fixture sections 25 will normally have lamps 27 extending longitudinally between them in the manner seen in FIGURE 4.

Directly above the angles 14 on each fixture are two sections of catwalk designated by the numeral 21. Each catwalk section is identical and extends approximately one-half the distance across the fixture.` The catwalk sections are preferably extruded of suitable metal and are provided with reinforcing ribs 22 which provide the requisite strength in a low weight structure. The catwalks are provided with hinged brackets 23 at their ends, and

the brackets 23 are connected by hinge bolts 24 to the upstanding webs of the angles 14. The yposition of the hinge bolts 24 is set inwardly from the tie rods 1f), so that the catwalks 21 may be pivoted upwardly and will rest against the tie rods in over-center position.

Fixed to the lower surface of each catwalk secti-on 21 is a reflector 28 of conventional design, mounted directly above the lamps 27 so as to provide the necessary illumination to the area below the light conductive panels 19. The refiectors 28 therefore move with the catwalk sections 21 so to attain the positions shown in dashed lines in FIGURE 1.

The present structure provides longitudinally aligned lamp fixtures in a continuous ceiling, and allows the fixtures to be maintained entirely by access above the false ceiling structure. The entire ceiling is completed as shown schematically in FIGURES 5 and 6. There are provided guard rails 32 at a suitable height along the tie rods 10 so as to provide a gripping surface for a person walking on the catwalk sections 21. There might also be transverse lixed catwalks connecting the fixtures at one or both ends of the room. There must also be an access -door or entry between the area separating'the true ceiling 11 and the false ceiling structure.

One gaining access to this area can then walk along the fixtures and may stand on one half of the catwalk sections 21 of the fixture and lift the other half for cleaning or changing the lamps 27. Raising of the catwalk section 21 also raises the reflector 28 fixed thereto, so that the lamp 27 is entirely accessible without the removal of any other product. However, should a fixed refiector mounting be desirable in a specific instance, this might also be provided by using the same catwalk and fixture structure. After one side of the fixture has been serviced, the catwalk vsection 21 above that side is lowered and the adjacent section can then be raised for servicing. The catwalk sections 21 are supported independently of one another and each is manufactured so as to be capable of supporting a man servicing the fixture.

Various modifications could be made in the design of this fixture while maintaining the basic concept of the construction. For this reason the exemplary structure described above is not intended to limit or restrict the scope of the invention, which is defined in the claims which follow.

Having thus described my invention, I claim:

1. In a lighting fixture:

a false ceiling structure mounted on supporting building members at an elevation below a true ceiling, said false ceiling including light transmitting panels;

lamp mounting means fixed to said false ceiling structure directly above said light transmitting panels;

lamps mounted on said lamp mounting means;

and catwalk means movably mounted on said false ceiling structure directly above said lamps to permit manual access to said lamps from a position above v said false ceiling.

2. In a lighting fixture:

a false ceiling structure hung by vertical rods at a level below the true ceiling, said false ceiling including light transmitting panels and transverse supports located above the panels at longitudinally spaced locations;

catwalk means pivotally connected to said supports, said catwalk means being movable from horizontal positions, resting on said supports, to off-center raised positions to permit access to the space beneath said catwalk means;

and lighting means mounted on said false ceiling structure in the space between said catwalk means and said panels.

3. The apparatus as defined in claim 2 further comprislng:

light reflector means fixed to the underside of said catwalk means directly above said lighting means when said catwalk means are at said horizontal positions.

4. In a lighting fixture:

a false ceiling structure hung by vertical rods at a level below the true ceiling, said false ceiling including a rectangular light transmitting panel and transverse supports located at each end of said panel at an elevation above the panel;

a lamp fixture fixed to said supports having longitudinal lamps mounted therebetween;

and a pair of complementary catwalk sections extending across the top of said supports in side by side portions along the full length of the lamps, said catwalk sections being movable relative to each other.

5. The apparatus as defined in claim 4 wherein said catwalk sections are independently mounted on said supports for rotation about transversely spaced longitudinal axes at the respective outside edges thereof.

n 6. The apparatus as defined in claim 5, further comprismg:

lamp reflectors fixed to the lower surfaces of said catwalk sections directly above said lamps when said catwalk sections are positioned on said supports above said fixtures.

7. The apparatus as defined in claim 4 wherein said lamp fixture comprises:

transverse lamp support members mounted on said false ceiling structure adapted to receive longitudinally positioned fluorescent lamps;

and enclosed wireways extending along the full length of each fixture in a continuous fashion at each transverse side thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,616,533 11/52 Gannett et al. 189-85 2,791,681 5/57 Dunker et al. 24U-51.11 2,926,237 2/ 60 Sorenson 240-9 EVON C. BLUNK, Primary Examiner, NORTON ANSHER, Examiner. 

1. IN A LIGHTING FIXTURE: A FALSE CEILING STRUCTURE MOUNTED ON SUPPORTING BUILDING MEMBERS AT AN ELEVATION BELOW A TRUE CEILING, SAID FALSE CEILING INCLUDING LIGHT TRANSMITTING PANELS; LAMP MOUNTING MEANS FIXED TO SAID FALSE CEILING STRUCTURE DIRECTLY ABOVE SAID LIGHT TRANSMITTING PANELS; LAMPS MOUNTED ON SAID LAMP MOUNTING MEANS; AND CATWALK MEANS MOVABLY MOUNED ON SAID FALSE CEILING STRUCTURE DIRECTLY ABOVE SAID LAMPS TO PERMIT MANUAL ACCESS TO SAID LAMPS FROM A POSITION ABOVE SAID FALSE CEILING. 